The Friendship Apartments (なかよしマンション Nakayoshi Manshon?) are an apartment complex in Furinkan where Hinako Ninomiya lives. Nakayoshi in Japanese means "good friend", hence the translation as "friendship". The exterior is decorated with stars, flowers, and zoo animals.
Hinako is shown asleep in her apartment while a female Ranma Saotome, Shampoo, Ukyo Kuonji, and Kodachi Kuno plan to defeat her the following day. However it is not revealed until later that she lives in the Friendship Apartments. She has a one bedroom apartment in the complex that gets incredibly messy because of her extremely short attention span. Notable items that she has are a Doraemon poster and a Super Famicom console. Ranma sneaked into her apartment to try and steal her goldfish bowl containing two male Siamese fighting fish which were giving her an enormous amount of ki, such that earlier that day she had blasted him and not returned to her child form. However the apartment was so messy that he took the time to clean it up, but did not find the bowl. When Hinako returned, he had to hide, but cleaned it up again when she made a mess and left to take a shower, taking the bowl with her. Hinako caught Ranma when she returned but he was able to snatch the bowl. However she blasted him through her front door just as Akane Tendo arrived to return Hinako's wallet.
After Akane beat up on Ranma Hinako expressed relief at recovering the bowl, revealing that even just a single male fighting fish generated an enormous amount of ki, so with two males the hostile ki emitted was endless. Hinako then tried to tutor Ranma in her adult form but he emptied the fish bowl into a rectangular tank, eliminating the circular opening and they ended up playing games. She was able to drain his ki using a broken fish scoop when he tried to leave and she returned the fish to the bowl, but had trouble staying awake due to the time, as it was past a little girl's bedtime. Further attempts were derailed by Hinako's lack of attention, as her body wanted to play but her heart wanted to teach. Ranma then suggested that they had to play hard before studying hard first. The two ended up playing games through the night, resulting in both falling asleep in class the next day.